demo_stokes-iterative

[gdmcbain]

Of particular interest in the Collection of documented demos #14 is 19. Stokes equations.

[gdmcbain]

I'm surprised that the zero pressure at the outflow is treated as a DirichletBC.

# Boundary condition for pressure at outflow
zero = Constant(0)
bc2 = DirichletBC(W.sub(1), zero, left)

cf. §4.1.4 ‘Variations on boundary conditions’ (Ern & Guermond 2004).

[gdmcbain]

 File "demo_stokes-iterative.py", line 53, in <module>
    W = V * Q
TypeError: unsupported operand type(s) for *: 'FunctionSpace' and 'FunctionSpace'

[gdmcbain]

I note that the Navier–Stokes examples in the tutorial (07, 08) didn't form such a product FunctionSpace.

[gdmcbain]

Ah, that was an old version (1.4.0) of Dolfin's documentation. Try the latest.